Ammonia, Nitrite, Nitrate and Bio-Balls

[JimBarr]

I have had FW aquariums for many years and recently started a saltwater tank. I see that my current tank is not large enough for some fish species that I wish to keep i.e. Yellow Tang. I am looking at a 75gal tank. I am wanting to do this right the first time. I plan on it being a mini-reef.

Reading these forums many people say that bio-balls, bio-wheels are bad and are the reefers enemy. They produce too many nitrates. The way I understand it is that fish waste and decomposition produce ammonia. Nature has provided us a bacteria that processes this and changes it into nitrite. Yet another bacteria turns the nitrite into nitrate. Nitrate, though harmless to fish unless it is in excessive quantities is deadly to inverts. The macroalgaes in refugiums will take care of nitrates.

My question is how is the presence of bio balls, wheels affect nitrates? They have no impact on the amount of ammonia that is being produced. The ammonia will eventually be changed to nitrate regardless if bio-balls are there or not.

 

[stresco]

I have BioBalls in my System now. I started a FOWLR and it spontainiously evolved into a Reef tank, so im am trying to removed them from my Wet\Dry. Since the very beginning, my nitrate levels have always been in the 20 to 30 range, wich is not bad for fish, but corals hate it. The bioballs IMO dont produce the nitrates, they act more like a sponge for them not allowing them to dissipate into the water. You want your nitrate levels to stay in the area of 0 -5 at all times and with the Bioballs, you will always have "high" nitrates in your system. If you are planning on going Reef, i would suggest leaving out the bioballs and getting 1.5 - 2 lbs of LR per every 1 gallon of tank water.

 

[JimBarr]

The bioballs IMO dont produce the nitrates, they act more like a sponge for them not allowing them to dissipate into the water

If this was the case, then the nitrate would not be present in the water to be tested. I would like to see evidence that bio-balls are bad. I still believe that at the start of the cycle with your bio-load you will still end up with nitrate whether the bacteria are growing on rock, substrate or bio-balls. The refuge is the answer to elimnating the nitrate. Let the plant life use it up.

 

[BillyZ]

this is how the nitrogen cycle works. fish produce amonia, backteria feed on the ammonia and produce nitrItes. Yet more bacteria feed on the nitrItes and produce nitrAtes. there are few bacteria the feed on nitrAtes. there ARE, however, bacteria that can USE the oxygen in nitrAtes to survive when they are denied disolved oxygen from the water.

This is why bio-ballss do not remove nitrAtes, as the bacteria on the bio-balls are served with plenty of oxygen so they feed on the nitrItes and ignore the nitrAtes.

When a system contains a DSB of at least 4", the lower portions of the sand bed become anerobic (lacking in oxygen) because the bacteria and critters above use up all the oxygen before the water gets down to them. The bacteria at these levels then NEED to get their oxygen in order to survive. the select group of bacteria that can do this, then take the oxygen from the nitrAtes and thus complete the nitrogen cycle. This last step can only happen in anerobic zones. Refugiums do help reduce the level of nitrates, but it's not so much the macro algaes as it is the additional DSB in them.


hope that helps clear things up.


BTW... Welcome to Aquarium Advice JimBarr

 

[steve-s]

Mind if I play too...

The bioballs IMO dont produce the nitrates, they act more like a sponge for them not allowing them to dissipate into the water

If this was the case, then the nitrate would not be present in the water to be tested. I would like to see evidence that bio-balls are bad. I still believe that at the start of the cycle with your bio-load you will still end up with nitrate whether the bacteria are growing on rock, substrate or bio-balls. The refuge is the answer to elimnating the nitrate. Let the plant life use it up.

I have posted to these kinds of question many times in the past and some agree while others cannot see the value of it but I will endevor to hopefully do this without a war.

There are two main problems with the incorrect use of a wet/dry system:
one
Bio Balls in a properly set up wet/dry system do not cause nitrates. Many that have sumps, place bio-balls in the sump free floating allowing them to collect detritus and rotting waste. If placed properly above the water line where the water can flow through the bio mass, it does not have enough contact time with the water to allow the collection of waste material which will permit the proper animals the chance to reduce it.

two
The reefkeeper themselves. More often than not, the failure of many filtration devices are not the fault of the equipment used but rather the amount of foods and types of foods fed to the tank. There is only one way for nitrates to be created and that is through elevated ammonia and nitrites. The bacterial chain is such>> nitrosomonas convert NH3 to NO2 where nitrobacters convert the NO2 to the less harmful form of NO3. Therefore by reducing the amount of ammonia created in the first place you by default reduce the amount of nitrate created. One cannot survive without the other.

This last step can only happen in anerobic zones. Refugiums do help reduce the level of nitrates, but it's not so much the macro algaes as it is the additional DSB in them.

A DSB is not the only way to complete the nitrogen cycle nor is an anaerobic set up the only way to do it. There is one type of bacteria that lives in both anaerobic as well as anoxic regions of the tank called facultative anaerobes. These facultative anaerobes can go back and forth between oxygen void (anaerobic) conditions as well as reduced O2 (anoxic) conditions. The anoxic areas are primarily the live rock and sand areas beneath the rock where water flow is not as easily accessed thereby feeding of O2 is much less available.

The bacteria in each case has a different feeding process. In an anoxic state, the bacteria feed primarily on available O2 and nitrates which are in turn converted to CO2 and nitrogen. In an anaerobic state these bacteria must consume other elements that that contain oxygen such as nitrates and sugars to survive. The conversion from nitrate is however not the same. The anaerobic bacteria instead produce the same CO2 and nitrogen but as well give off hydrogen sulphides and methane gas.

Providing there is sufficient amounts of live rock and animals specifically introduced to reduce waste matter, as little as 1" of sand can and will be enough to allow nitrogen to form.

If the tank is set up properly, not overcrowded and maintained regularly you can have a successful tank. It really comes down to how you plan the tank as a functioning ecosystem and how mindful you are of what goes into it.

Cheers
Steve